Measles Virus Genome Research Articles

Complete Genome Characterization of Two Wild-Type Measles Viruses from Vietnamese Infants during the 2014 Outbreak.

A large measles virus outbreak occurred across Vietnam in 2014. We identified and obtained complete measles virus genomes in stool samples collected from two diarrheal pediatric patients in Dong Thap Province. These are the first complete genome sequences of circulating measles viruses in Vietnam during the 2014 measles outbreak.

Abstract B040: Oncolytic measles virus for tumor vaccination

Abstract The concept of tumor vaccination is based on the induction of robust immune responses against tumor-associated antigens (TAA) selectively expressed within the tumor. Whereas in the case of foreign antigens an immune response can be induced quite easily, induction of appropriate immunity against self-antigens needs potent antigen presentation to break immune tolerance. Tumor vaccines may be further improved by utilizing the properties of oncolytic viruses (OVs), that selectively replicate within and destroy tumor tissue and may further enhance the vaccination effects by supplying danger signals in situ and stimulating the immune system. Immunogenic OVs additionally delivering a specific TAA by in situ antigen presentation can break immmune tolerance, induce a specifically redirected immune response, and thereby may increase therapeutic efficacy. Attenuated measles virus (MV) derived from a vaccine strain is currently tested as oncolytic virotherapeutic in clinical trials. Recombinant MVs additionally reveal excellent vaccine characteristics per se, inducing potent and long lasting immune responses against endogenous and foreign antigens, if the latter are additionally expressed by the recombinant virus. Therefore, we develop and aim to validate novel prototypic replicating MV for simultaneous oncolysis and in situ tumor vaccination. For that purpose, a well characterized tumor-confined TAA of the claudin family is used as vaccination target antigen (GNTP01). Different antigen formats or epitopes of GNTP01 were cloned into the MV genome and recombinant viruses were generated, which express those epitopes in different amounts as expected due to positional effects of the additional transcription units either behind the P (post P) or the H (post H) gene cassettes of Moraten vaccine strain-derived MVvac2 genome, presented on in situ produced particles or not. Based on these data, selected viruses expressing different antigen formats have been chosen for further characterization. The selected viruses were amplified, and unimpaired growth and genetic stability of the inserted TAA were demonstrated. To test their immunogenic properties, MV-susceptible IFNAR-/--CD46Ge mice have been immunized with the different viruses, and humoral as well as cellular immune responses are currently analyzed. In parallel, an immune competent, syngeneic tumor model has been established by employment of transgenic C57/BL6-derived tumor cell lines expressing the target antigen as well as MV-receptors. For three different transgenic tumor cell lines antigen expression and tumorigenicity in MV-susceptible animals has been confirmed. Such tumor-bearing animals will be used for analysis of induced immune responses, anti-tumoral activity, and therapeutic efficacy after immunization with selected viruses that have been shown to induce significant humoral or cellular immune responses. Once the proof-of-concept has been established this innovative oncolytic virus-based approach holds the potential for a novel therapeutic technology platform that synergistically combines the direct tumor-lytic properties of recombinant MVs with the therapeutic induction of potent immune responses depending on the patient´s TAA expression profile. Citation Format: Stefan Hutzler, Stephanie Erbar, Robert A. Jabulowsky, Tim Beissert, Jan Hanauer, Oezlem Tuereci, Rita Mitnacht-Kraus, Sebastian Kreiter, Mustafa Diken, Cedrik M. Britten, Ugur Sahin, Michael D. Muehlebach. Oncolytic measles virus for tumor vaccination. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B040.

Measles Virus Epitope Presentation by HLA: Novel Insights into Epitope Selection, Dominance, and Microvariation.

Immunity to infections with measles virus (MV) can involve vigorous human leukocyte antigen (HLA) class I-restricted CD8+ cytotoxic T cell (CTL) responses. MV, albeit regarded monotypic, is known to undergo molecular evolution across its RNA genome. To address which regions of the MV proteome are eligible for recognition by CD8+ CTLs and how different HLA class I loci contribute to the epitope display, we interrogated the naturally processed and presented MV peptidome extracted from cell lines expressing in total a broad panel of 16 different common HLA-A, -B, and -C molecules. The repertoire and abundance of MV peptides were bona fide identified by nanoHPLC–MS/MS. ­Eighty-nine MV peptides were discovered and assignment to an HLA-A, -B, or -C allele, based on HLA-peptide affinity prediction, was in most cases successful. Length variation and presentation by multiple HLA class I molecules was common in the MV peptidome. More than twice as many unique MV epitopes were found to be restricted by HLA-B than by HLA-A, while MV peptides with supra-abundant expression rates (>5,000 cc) were rather associated with HLA-A and HLA-C. In total, 59 regions across the whole MV proteome were identified as targeted by HLA class I. Sequence coverage by epitopes was highest for internal proteins transcribed from the MV-P/V/C and -M genes and for hemagglutinin. At the genome level, the majority of the HLA class I-selected MV epitopes represented codons having a higher non-synonymous mutation rate than silent mutation rate, as established by comparison of a set of 58 unique full length MV genomes. Interestingly, more molecular variation was seen for the epitopes expressed at rates ≥1,000 cc. These data for the first time indicate that HLA class I broadly samples the MV proteome and that CTL pressure may contribute to the genomic evolution of MV.

Phylogenetic and epidemiological analysis of measles outbreaks in Denmark, 2013 to 2014.

Despite the introduction of safe, effective vaccines decades ago and joint global public health efforts to eliminate measles, this vaccine-preventable disease continues to pose threats to children's health worldwide. During 2013 and 2014, measles virus was introduced into Denmark through several independent importations. This resulted in a number of secondary cases (n=7), with two clusters in 2013 and one in 2014. In total, there were 44 cases of measles. Most cases (n=41) were laboratory confirmed by detection of measles virus genome by real-time reverse transcription (RT)-PCR and IgM antibodies. The viruses from confirmed cases were genotyped by sequencing. Only one genotype circulated each year, i.e. D8 and B3, respectively. Sequencing of measles virus from different clinical specimens from the same patients revealed that sequence variants of measles viruses might co-exist and co-transmit during an outbreak. The majority of the cases were unvaccinated (n=27) or recipients of one dose of measles-mumps-rubella (MMR) vaccine (n=7). In addition, two fully vaccinated adult cases were reported in 2014. We demonstrate the transmission of measles virus in a population in which the two-dose MMR vaccination coverage rate was 80% and how even vaccinated individuals may be at risk of contracting measles once transmission has been established.

Advances in the design and development of oncolytic measles viruses

A successful oncolytic virus is one that selectively propagates and destroys cancerous tissue without causing excessive damage to the normal surrounding tissue. Oncolytic measles virus (MV) is one such virus that exhibits this characteristic and thus has rapidly emerged as a potentially useful anticancer modality. Derivatives of the Edmonston MV vaccine strain possess a remarkable safety record in humans. Promising results in preclinical animal models and evidence of biological activity in early phase trials contribute to the enthusiasm. Genetic modifications have enabled MV to evolve from a vaccine agent to a potential anticancer therapy. Specifically, alterations of the MV genome have led to improved tumor selectivity and delivery, therapeutic potency, and immune system modulation. In this article, we will review the advancements that have been made in the design and development of MV that have led to its use as a cancer therapy. In addition, we will discuss the evidence supporting its use, as well as the challenges associated with MV as a potential cancer therapeutic.

Mutational Analysis of Measles Virus Suggests Constraints on Antigenic Variation of the Glycoproteins.

Measles virus undergoes error-prone replication like other RNA viruses, but over time, it has remained antigenically monotypic. The constraints on the virus that prevent the emergence of antigenic variants are unclear. As a first step in understanding this question, we subjected the measles virus genome to unbiased insertional mutagenesis, and viruses that could tolerate insertions were rescued. Only insertions in the nucleoprotein, phosphoprotein, matrix protein, as well as intergenic regions were easily recoverable. Insertions in the glycoproteins of measles virus were severely under-represented in our screen. Host immunity depends on developing neutralizing antibodies to the hemagglutinin and fusion glycoproteins; our analysis suggests that these proteins occupy very little evolutionary space and therefore have difficulty changing in the face of selective pressures. We propose that the inelasticity of these proteins prevents the sequence variation required to escape antibody neutralization in the host, allowing for long-lived immunity after infection with the virus.

Cooperative Interaction Within RNA Virus Mutant Spectra.

RNA viruses usually consist of mutant spectra because of high error rates of viral RNA polymerases. Growth competition occurs among different viral variants, and the fittest clones predominate under given conditions. Individual variants, however, may not be entirely independent of each other, and internal interactions within mutant spectra can occur. Examples of cooperative and interfering interactions that exert enhancing and suppressing effects on replication of the wild-type virus, respectively, have been described, but their underlying mechanisms have not been well defined. It was recently found that the cooperation between wild-type and variant measles virus genomes produces a new phenotype through the heterooligomer formation of a viral protein. This observation provides a molecular mechanism underlying cooperative interactions within mutant spectra. Careful attention to individual sequences, in addition to consensus sequences, may disclose further examples of internal interactions within mutant spectra.

Newly Developed Measles Viral Vector Can Efficiently Transduce Multiple Genes into naïve T Cells

Because blood cells can be obtained with relatively easy and safe procedure, they have been routinely used for transfusion and transplantation purposes. And they are now considered as attractive cell sources for developing new gene therapies including cancer therapy using various immune cells, and regenerative therapy using hematopoietic stem cells or induced pluripotent stem cells (iPS) cells. For example, chimeric antigen receptor modified autologous T cells have been considered as effective therapy for various cancers. And iPS cells have been easily established from peripheral T cells for the purpose of treating various diseases. However, in spite of these possibilities, the development of the safer and more efficient genetic modification methods of hematopoietic cells is imminent. In this study, we developed the novel measles viral (MV) vector which enables us to transduce multiple genes into immune cells. The wild type measles virus is one of the aerosol-transmitted viruses and has strong infectious capacity to immune cells, and epithelial cells via signaling lymphocyte activation molecule (SLAM) or nectin-4. First, we modified the wild type measles virus genome to non-transmissible and non-lytic, and equipped with the ability of transducing multiple genes, at most six genes, into target cells. Briefly, the intrinsically non-segmented wild type virus genome was divided into two segments and point mutations were introduced into the virus genes encoding hemagglutinin and the matrix protein. Moreover, as the fusion protein gene was removed from the virus genome, the virus could not replicate in neighbor cells. We examined the gene transduction efficiency of the gene modified measles virus (H8-Fd-MV vector) into hematopoietic cells. We first constructed the H8-Fd-MV vector with GFP gene and transduced into hematopoietic progenitor cells and immune cells from human cord blood and peripheral blood. We observed that almost all of HPCs from cord blood (99.7% in floating cells expressed CD34), T cells (99.9% in CD3+ cells), and B cells (98.2% in CD19+ cells) from peripheral blood expressed GFP at two days after the transduction. Especially, to express GFP gene in human peripheral T cells, it was not necessary to pre-stimulate them with CD3/CD28 beads (99.6% in stimulating T cells (72.9% in SLAM+ cells) v.s. 82.6 % in non-stimulating cells (37.4% in SLAM+ cells)). T cells from cord blood showed almost all naïve phenotype (CD4+ cells: 93.2±1.8% in CD45RA+CCR7+ cells, 1.7±1.1% in CD45RA+CCR7- cells; CD8+ cells: 41.6±5.7% in CD45RA+CCR7+ cells, and 41.9±11.0% in CD8+CD45RA+CCR7- cells) and T cells transduced by MV vector expressed GFP more (CD4+ cells: 80.3±13.7%, and CD8+ cells: 82.5±8.5%) than those transduced by Sendai viral vector (CD4+ cells: 15.5±0.7%, and CD8+ cells: 17.4±5.4%). These data suggested that H8-Fd-MV vector could transduce GFP gene efficiently into various T cell lineages including naïve T cells, which had been difficult to be transduced with classical gene transduction methods. We next generated H8-Fd-MV vector for expressing 6 genes (OCT4, SOX2, KLF4, L-MYC, PIN1, and GFP) and transduced into stimulated T cells. After 3 days, GFP+ T cells expressed all of these 6 genes. We also detected that more than 50% of the stimulated T cells with IL-2 expressed GFP at 14 days after the transduction. After 27 days from transfection, embryonic stem cell (ES cell)-like colonies were picked up and analyzed the character. These cells showed ES cell morphology over 20 times passages and expressed pluripotent marker (NANOG, OCT4, Tra-1-60, Tra-1-81). We also found T cell receptor rearrangements in these cells. Embryoid bodies from these cells expressed three germ line markers in vitro. We next examined the hematopoietic differentiation of these cells using coculture system with murine embryonic aorta-gonad-mesonephros region-derived stromal cell line (AGM-3 cells). The co-cultured cells harvested at day 12 expressed CD34 and CD45. These data suggested that we established iPS cells from terminal differentiated T cells using H8-Fd-MV vector for expressing reprogramming factor.These results indicated that multiple genes were expressed efficiently in immune cells using H8-Fd-MV vector. Highly efficient transduction ability of MV vector for T cells would enable us to develop new gene therapy targeting cancer using gene modified T cells as well as organ regeneration using iPS cells. DisclosuresNo relevant conflicts of interest to declare.

Biased hypermutation occurred frequently in a gene inserted into the IC323 recombinant measles virus during its persistence in the brains of nude mice

Measles virus (MV) is the causative agent of measles and its neurological complications, subacute sclerosing panencephalitis (SSPE) and measles inclusion body encephalitis (MIBE). Biased hypermutation in the M gene is a characteristic feature of SSPE and MIBE. To determine whether the M gene is the preferred target of hypermutation, an additional transcriptional unit containing a humanized Renilla reniformis green fluorescent protein (hrGFP) gene was introduced into the IC323 MV genome, and nude mice were inoculated intracerebrally with the virus. Biased hypermutation occurred in the M gene and also in the hrGFP gene when it was inserted between the leader and the N gene, but not between the H and L gene. These results indicate that biased hypermutation is usually found in a gene whose function is not essential for viral proliferation in the brain and that the location of a gene in the MV genome can affect its mutational frequency.

Wild-type measles viruses with non-standard genome lengths.

The length of the single stranded, negative sense RNA genome of measles virus (MeV) is highly conserved at 15,894 nucleotides (nt). MeVs can be grouped into 24 genotypes based on the highly variable 450 nucleotides coding for the carboxyl-terminus of the nucleocapsid protein (N-450). Here, we report the genomic sequences of 2 wild-type viral isolates of genotype D4 with genome lengths of 15,900 nt. Both genomes had a 7 nt insertion in the 3′ untranslated region (UTR) of the matrix (M) gene and a 1 nt deletion in the 5′ UTR of the fusion (F) gene. The net gain of 6 nt complies with the rule-of-six required for replication competency of the genomes of morbilliviruses. The insertions and deletion (indels) were confirmed in a patient sample that was the source of one of the viral isolates. The positions of the indels were identical in both viral isolates, even though epidemiological data and the 3 nt differences in N-450 between the two genomes suggested that the viruses represented separate chains of transmission. Identical indels were found in the M-F intergenic regions of 14 additional genotype D4 viral isolates that were imported into the US during 2007–2010. Viral isolates with and without indels produced plaques of similar size and replicated efficiently in A549/hSLAM and Vero/hSLAM cells. This is the first report of wild-type MeVs with genome lengths other than 15,894 nt and demonstrates that the length of the M-F UTR of wild-type MeVs is flexible.

Relationship Between Measles Outbreaks Based on Genetic Analysis of Measles Virus Genomes Detected in Patients in Poland between 2006 and 2012

This study describes the molecular characterization of 56 MeV strains obtained from 56 patients in Poland from 2006 to 2012. The C-terminal fragment of nucleoprotein gene was analysed. It has been found out during 2006 and 20012 MeV strains circulating in Poland belonged to genotypes D4, D5, D6 and B3. The D4 strains isolated in Poland were different from any other D4 strain circulating at the same time in Europe, whereas all other MeV strains isolated during 2007-2012 were related to strains from other countries. The present data suggest that after 2006 the MeV strains were imported.

Evaluation of Inhibitory Effects of Berberine on Apoptosis Due to Measles Virus Strain AIK-HDC

Background: Measles virus (MV) is a highly contagious agent which causes a major health problem in developing countries. We studied the effect of BERBERINE on the replication of an AIK-HDC strain of MV and its induced apoptosis in Vero cell lines. Methods: In this study, toxicity of BERBERINE on Vero cells was investigated first, resulted in determination of sub-lethal or non-toxic concentration zone of BERBERINE for cells. Next, anti-viral effect of BERBERINE at various time limits was evaluated and virus titer was determined at each stage either as 50 tissue culture infective dose TCID50 or by plaque assay method. Using specific anti-measles IgG, anti-viral effect of BERBERINE on MV replication cycle was evaluated through indirect immunofluorescence assay, meanwhile presence of viral RNA was investigated by RT-PCR and gel- electrophoresis. Results: According to the experiments, BERBERINE, at concentration of 50 mM, markedly inhibited the cytopathic effect (CPE) induced by MV. BERBERINE also significantly inhibited apoptosis induced by MV. BERBERINE either influences replication of MV genome, or may inhibit virion formation. Conclusion: These results suggest that the inhibition of CPE and apoptosis by BERBERINE induced by MV may be associated with the effect of BERBERINE on viral RNA genome. Therefore, it is suggested that MV infections can induce apoptosis through the activation of a common pathway that can be blocked by BERBERINE or some of its ingredients.

Evaluation of Measles Vaccine Virus as a Vector to Deliver Respiratory Syncytial Virus Fusion Protein or Epstein-Barr Virus Glycoprotein gp350

Live attenuated recombinant measles vaccine virus (MV) Edmonston-Zagreb (EZ) strain was evaluated as a viral vector to express the ectodomains of fusion protein of respiratory syncytial virus (RSV F) or glycoprotein 350 of Epstein-Barr virus (EBV gp350) as candidate vaccines for prophylaxis of RSV and EBV. The glycoprotein gene was inserted at the 1st or the 3rd position of the measles virus genome and the recombinant viruses were generated. Insertion of the foreign gene at the 3rd position had a minimal impact on viral replication in vitro. RSV F or EBV gp350 protein was secreted from infected cells. In cotton rats, EZ-RSV F and EZ-EBV gp350 induced MV- and insert-specific antibody responses. In addition, both vaccines also induced insert specific interferon gamma (IFN-γ) secreting T cell response. EZ-RSV F protected cotton rats from pulmonary replication of RSV A2 challenge infection. In rhesus macaques, although both EZ-RSV F and EZ-EBV gp350 induced MV specific neutralizing antibody responses, only RSV F specific antibody response was detected. Thus, the immunogenicity of the foreign antigens delivered by measles vaccine virus is dependent on the nature of the insert and the animal models used for vaccine evaluation.

Intrinsic disorder in measles virus nucleocapsids

The genome of measles virus is encapsidated by multiple copies of the nucleoprotein (N), forming helical nucleocapsids of molecular mass approaching 150 Megadalton. The intrinsically disordered C-terminal domain of N (N(TAIL)) is essential for transcription and replication of the virus via interaction with the phosphoprotein P of the viral polymerase complex. The molecular recognition element (MoRE) of N(TAIL) that binds P is situated 90 amino acids from the folded RNA-binding domain (N(CORE)) of N, raising questions about the functional role of this disordered chain. Here we report the first in situ structural characterization of N(TAIL) in the context of the entire N-RNA capsid. Using nuclear magnetic resonance spectroscopy, small angle scattering, and electron microscopy, we demonstrate that N(TAIL) is highly flexible in intact nucleocapsids and that the MoRE is in transient interaction with N(CORE). We present a model in which the first 50 disordered amino acids of N(TAIL) are conformationally restricted as the chain escapes to the outside of the nucleocapsid via the interstitial space between successive N(CORE) helical turns. The model provides a structural framework for understanding the role of N(TAIL) in the initiation of viral transcription and replication, placing the flexible MoRE close to the viral RNA and, thus, positioning the polymerase complex in its functional environment.

The F gene of the Osaka-2 strain of measles virus derived from a case of subacute sclerosing panencephalitis is a major determinant of neurovirulence.

Measles virus (MV) is the causative agent for acute measles and subacute sclerosing panencephalitis (SSPE). Although numerous mutations have been found in the MV genome of SSPE strains, the mutations responsible for the neurovirulence have not been determined. We previously reported that the SSPE Osaka-2 strain but not the wild-type strains of MV induced acute encephalopathy when they were inoculated intracerebrally into 3-week-old hamsters. The recombinant MV system was adapted for the current study to identify the gene(s) responsible for neurovirulence in our hamster model. Recombinant viruses that contained envelope-associated genes from the Osaka-2 strain were generated on the IC323 wild-type MV background. The recombinant virus containing the M gene alone did not induce neurological disease, whereas the H gene partially contributed to neurovirulence. In sharp contrast, the recombinant virus containing the F gene alone induced lethal encephalopathy. This phenotype was related to the ability of the F protein to induce syncytium formation in Vero cells. Further study indicated that a single T461I substitution in the F protein was sufficient to transform the nonneuropathogenic wild-type MV into a lethal virus for hamsters.

The Matrix Protein of Measles Virus Regulates Viral RNA Synthesis and Assembly by Interacting with the Nucleocapsid Protein

The genome of measles virus (MV) is encapsidated by the nucleocapsid (N) protein and associates with RNA-dependent RNA polymerase to form the ribonucleoprotein complex. The matrix (M) protein is believed to play an important role in MV assembly by linking the ribonucleoprotein complex with envelope glycoproteins. Analyses using a yeast two-hybrid system and coimmunoprecipitation in mammalian cells revealed that the M protein interacts with the N protein and that two leucine residues at the carboxyl terminus of the N protein (L523 and L524) are critical for the interaction. In MV minigenome reporter gene assays, the M protein inhibited viral RNA synthesis only when it was able to interact with the N protein. The N protein colocalized with the M protein at the plasma membrane when the proteins were coexpressed in plasmid-transfected or MV-infected cells. In contrast, the N protein formed small dots in the perinuclear area when it was expressed without the M protein, or it was incapable of interacting with the M protein. Furthermore, a recombinant MV possessing a mutant N protein incapable of interacting with the M protein grew much less efficiently than the parental virus. Since the M protein has an intrinsic ability to associate with the plasma membrane, it may retain the ribonucleoprotein complex at the plasma membrane by binding to the N protein, thereby stopping viral RNA synthesis and promoting viral particle production. Consequently, our results indicate that the M protein regulates MV RNA synthesis and assembly via its interaction with the N protein.

Converting Tumor-specific Markers Into Reporters of Oncolytic Virus Infection

Preferential killing of transformed cells, while keeping normal cells and organs unharmed, is the main goal of cancer gene therapy. Genetically engineered trackable markers and imaging reporters enable noninvasive monitoring of transduction efficiency and pharmacokinetics of anticancer virotherapeutics. However, none of these reporters can differentiate between infection in the targeted tumors and that in the normal tissue. Thus, we constructed oncolytic measles virus (MV) armed with a human light immunoglobulin chain reporter gene for the treatment of multiple myeloma (MM). Excessive production of monoclonal immunoglobulin is a key characteristic and marker for diagnostics of MM. Once expressed in infected target cells, vector-encoded lambda protein recombines with myeloma IgG-kappa immunoglobulin creating a unique IgG-kappa/lambda. A modified immunoassay technique allows precise quantification of converted marker molecules. Only antibody producing cells were able to assemble this chimeric immunoglobulin molecule, whereas other cells secreted only free lambda light chain. Human myeloma xenografts inoculated with lambda chain expressing MV secreted converted IgG-kappa/lambda in the plasma of tumor bearing animals and elevated reporter levels correlated with response to the therapy. This is the first report of a gene therapy vector engineered to discriminate between infection in malignant and normal cells by molecular modification of a tumor-specific protein.

The interaction between the measles virus nucleoprotein and the Interferon Regulator Factor 3 relies on a specific cellular environment

BackgroundThe genome of measles virus consists of a non-segmented single-stranded RNA molecule of negative polarity, which is encapsidated by the viral nucleoprotein (N) within a helical nucleocapsid. The N protein possesses an intrinsically disordered C-terminal domain (aa 401–525, NTAIL) that is exposed at the surface of the viral nucleopcapsid. Thanks to its flexible nature, NTAIL interacts with several viral and cellular partners. Among these latter, the Interferon Regulator Factor 3 (IRF-3) has been reported to interact with N, with the interaction having been mapped to the regulatory domain of IRF-3 and to NTAIL. This interaction was described to lead to the phosphorylation-dependent activation of IRF-3, and to the ensuing activation of the pro-immune cytokine RANTES gene.ResultsAfter confirming the reciprocal ability of IRF-3 and N to be co-immunoprecipitated in 293T cells, we thoroughly investigated the NTAIL-IRF-3 interaction using a recombinant, monomeric form of the regulatory domain of IRF-3. Using a large panel of spectroscopic approaches, including circular dichroism, fluorescence spectroscopy, nuclear magnetic resonance and electron paramagnetic resonance spectroscopy, we failed to detect any direct interaction between IRF-3 and either full-length N or NTAIL under conditions where these latter interact with the C-terminal X domain of the viral phosphoprotein. Furthermore, such interaction was neither detected in E. coli nor in a yeast two hybrid assay.ConclusionAltogether, these data support the requirement for a specific cellular environment, such as that provided by 293T human cells, for the NTAIL-IRF-3 interaction to occur. This dependence from a specific cellular context likely reflects the requirement for a human or mammalian cellular co-factor.

The 30th anniversary of quasispecies

The meeting on ‘Quasispecies: past, present and future’ took place between 17 and 18 November 2008, in Barcelona, Spain, and was organized by J. Gomez, C. Lopez‐Galindez, M.A. Martinez & A. Mas. ![][1] A meeting was held in Barcelona, Spain, in November 2008 to celebrate the 30th anniversary of the publication of the article that described the extensive genetic heterogeneity of bacteriophage Qβ (Domingo et al , 1978), which is considered to mark the beginning of experimental studies on viral quasispecies. This meeting was held at the impressive fifteenth century building of the ancient Hospital de la Santa Creu in the old town of Barcelona, which is now the headquarters of the Institut d'Estudis Catalans, and was attended by C. Weissmann (Jupiter, FL, USA), M. Billeter (Zurich, Switzerland) and E. Domingo (Madrid, Spain), who were three early protagonists of the phage Qβ work at the University of Zurich in the 1970s. Several speakers presented their results on the theoretical aspects of the population dynamics of cells and viruses, the clinical implications of quasispecies, and extensions of the quasispecies concept to cellular genes and prions. The meeting was introduced by A. Mas (Albacete, Spain), who reflected on the increasing impact that quasispecies have had in the scientific literature over the past three decades, and quoted some of the key references on viral quasispecies (Martell et al , 1992; Meyerhans et al , 1989; Najera et al , 1995; Vignuzzi et al , 2006; for a historical review of the impact of quasispecies in virology, see Holland, 2006). The scientific presentations were opened by Weissmann and Domingo, who were the last and first authors of the 1978 paper, respectively. Their talks conveyed the scientific atmosphere of the 1970s—when molecular biology was carried out with few recombinant‐DNA techniques—to a young audience. Nucleic‐acid sequencing was in … [1]: /embed/graphic-1.gif

Application of a simple method for the detection of measles virus genome by loop-mediated isothermal amplification (LAMP)

A new simple RT-LAMP method was applied to detect measles virus nucleic acid and compared with nest-RT-PCR. Compare the detection rate of the RT-LAMP method with that of nest-RT-PCR by detecting measles virus nucleic acid from measles virus and clinical samples. The nucleic acid positive rates of all 23 strains of measles virus are all 100% by the two methods. But to the detection of 18 clinical samples which are negative in measles isolation, the nest-RT-LAMP showed 56.52% positive rate of nucleic acid of measles virus and nest-RT-PCR showed 47.83%. RT-LAMP is more sensitive than nest-RT-PCR.